[FFmpeg-devel] [PATCH v2 3/5] avformat/hls: add http_persistent option
Aman Gupta
ffmpeg at tmm1.net
Wed Dec 13 02:35:09 EET 2017
From: Aman Gupta <aman at tmm1.net>
This teaches the HLS demuxer to use the HTTP protocols
multiple_requests=1 option, to take advantage of "Connection:
Keep-Alive" when downloading playlists and segments from the HLS server.
With the new option, you can avoid TCP connection and TLS negotiation
overhead, which is particularly beneficial when streaming via a
high-latency internet connection.
Similar to the http_persistent option recently implemented in hlsenc.c
---
doc/demuxers.texi | 3 +++
libavformat/hls.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 67 insertions(+), 4 deletions(-)
diff --git a/doc/demuxers.texi b/doc/demuxers.texi
index 73dc0feec1..18ff7101ac 100644
--- a/doc/demuxers.texi
+++ b/doc/demuxers.texi
@@ -316,6 +316,9 @@ segment index to start live streams at (negative values are from the end).
@item max_reload
Maximum number of times a insufficient list is attempted to be reloaded.
Default value is 1000.
+
+ at item http_persistent
+Use persistent HTTP connections. Applicable only for HTTP streams.
@end table
@section image2
diff --git a/libavformat/hls.c b/libavformat/hls.c
index ab6ff187a6..5c1895c180 100644
--- a/libavformat/hls.c
+++ b/libavformat/hls.c
@@ -26,6 +26,7 @@
* http://tools.ietf.org/html/draft-pantos-http-live-streaming
*/
+#include "libavformat/http.h"
#include "libavutil/avstring.h"
#include "libavutil/avassert.h"
#include "libavutil/intreadwrite.h"
@@ -94,6 +95,7 @@ struct playlist {
AVIOContext pb;
uint8_t* read_buffer;
AVIOContext *input;
+ int input_read_done;
AVFormatContext *parent;
int index;
AVFormatContext *ctx;
@@ -206,6 +208,8 @@ typedef struct HLSContext {
int strict_std_compliance;
char *allowed_extensions;
int max_reload;
+ int http_persistent;
+ AVIOContext *playlist_pb;
} HLSContext;
static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
@@ -256,6 +260,7 @@ static void free_playlist_list(HLSContext *c)
av_freep(&pls->pb.buffer);
if (pls->input)
ff_format_io_close(c->ctx, &pls->input);
+ pls->input_read_done = 0;
if (pls->ctx) {
pls->ctx->pb = NULL;
avformat_close_input(&pls->ctx);
@@ -640,7 +645,24 @@ static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
else if (strcmp(proto_name, "file") || !strncmp(url, "file,", 5))
return AVERROR_INVALIDDATA;
- ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
+ if (c->http_persistent && *pb && av_strstart(proto_name, "http", NULL)) {
+ URLContext *uc = ffio_geturlcontext(*pb);
+ av_assert0(uc);
+ (*pb)->eof_reached = 0;
+ ret = ff_http_do_new_request(uc, url);
+ if (ret == AVERROR_EXIT) {
+ ff_format_io_close(c->ctx, &c->playlist_pb);
+ return ret;
+ } else if (ret < 0) {
+ av_log(s, AV_LOG_WARNING,
+ "keepalive request failed for '%s', retrying with new connection: %s\n",
+ url, av_err2str(ret));
+ ff_format_io_close(c->ctx, pb);
+ ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
+ }
+ } else {
+ ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
+ }
if (ret >= 0) {
// update cookies on http response with setcookies.
char *new_cookies = NULL;
@@ -683,10 +705,27 @@ static int parse_playlist(HLSContext *c, const char *url,
char tmp_str[MAX_URL_SIZE];
struct segment *cur_init_section = NULL;
+ if (!in && c->http_persistent && c->playlist_pb) {
+ in = c->playlist_pb;
+ URLContext *uc = ffio_geturlcontext(in);
+ av_assert0(uc);
+ in->eof_reached = 0;
+ ret = ff_http_do_new_request(uc, url);
+ if (ret == AVERROR_EXIT) {
+ ff_format_io_close(c->ctx, &c->playlist_pb);
+ return ret;
+ } else if (ret < 0) {
+ av_log(c->ctx, AV_LOG_WARNING,
+ "keepalive request failed for '%s', retrying with new connection: %s\n",
+ url, av_err2str(ret));
+ ff_format_io_close(c->ctx, &c->playlist_pb);
+ in = NULL;
+ }
+ }
+
if (!in) {
#if 1
AVDictionary *opts = NULL;
- close_in = 1;
/* Some HLS servers don't like being sent the range header */
av_dict_set(&opts, "seekable", "0", 0);
@@ -696,10 +735,18 @@ static int parse_playlist(HLSContext *c, const char *url,
av_dict_set(&opts, "headers", c->headers, 0);
av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
+ if (c->http_persistent)
+ av_dict_set(&opts, "multiple_requests", "1", 0);
+
ret = c->ctx->io_open(c->ctx, &in, url, AVIO_FLAG_READ, &opts);
av_dict_free(&opts);
if (ret < 0)
return ret;
+
+ if (c->http_persistent)
+ c->playlist_pb = in;
+ else
+ close_in = 1;
#else
ret = open_in(c, &in, url);
if (ret < 0)
@@ -1111,6 +1158,9 @@ static int open_input(HLSContext *c, struct playlist *pls, struct segment *seg)
av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
av_dict_set(&opts, "seekable", "0", 0);
+ if (c->http_persistent)
+ av_dict_set(&opts, "multiple_requests", "1", 0);
+
if (seg->size >= 0) {
/* try to restrict the HTTP request to the part we want
* (if this is in fact a HTTP request) */
@@ -1316,7 +1366,7 @@ restart:
if (!v->needed)
return AVERROR_EOF;
- if (!v->input) {
+ if (!v->input || (c->http_persistent && v->input_read_done)) {
int64_t reload_interval;
struct segment *seg;
@@ -1368,6 +1418,7 @@ reload:
goto reload;
}
+ v->input_read_done = 0;
seg = current_segment(v);
/* load/update Media Initialization Section, if any */
@@ -1405,7 +1456,11 @@ reload:
return ret;
}
- ff_format_io_close(v->parent, &v->input);
+ if (c->http_persistent) {
+ v->input_read_done = 1;
+ } else {
+ ff_format_io_close(v->parent, &v->input);
+ }
v->cur_seq_no++;
c->cur_seq_no = v->cur_seq_no;
@@ -1666,6 +1721,7 @@ static int hls_close(AVFormatContext *s)
free_rendition_list(c);
av_dict_free(&c->avio_opts);
+ ff_format_io_close(c->ctx, &c->playlist_pb);
return 0;
}
@@ -1903,6 +1959,7 @@ static int recheck_discard_flags(AVFormatContext *s, int first)
} else if (first && !cur_needed && pls->needed) {
if (pls->input)
ff_format_io_close(pls->parent, &pls->input);
+ pls->input_read_done = 0;
pls->needed = 0;
changed = 1;
av_log(s, AV_LOG_INFO, "No longer receiving playlist %d\n", i);
@@ -2137,6 +2194,7 @@ static int hls_read_seek(AVFormatContext *s, int stream_index,
struct playlist *pls = c->playlists[i];
if (pls->input)
ff_format_io_close(pls->parent, &pls->input);
+ pls->input_read_done = 0;
av_packet_unref(&pls->pkt);
reset_packet(&pls->pkt);
pls->pb.eof_reached = 0;
@@ -2191,6 +2249,8 @@ static const AVOption hls_options[] = {
INT_MIN, INT_MAX, FLAGS},
{"max_reload", "Maximum number of times a insufficient list is attempted to be reloaded",
OFFSET(max_reload), AV_OPT_TYPE_INT, {.i64 = 1000}, 0, INT_MAX, FLAGS},
+ {"http_persistent", "Use persistent HTTP connections",
+ OFFSET(http_persistent), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, FLAGS },
{NULL}
};
--
2.14.3 (Apple Git-98)
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